Method of preparing metallo-silicates



P 1930. A. s. BEHRMAN 1,756,625

METHOD OF PREPARING IETALLO-SILICATES Filed April 11, 1925 5022x3131 Car b/hens Jeff/n9 Facep'lule ill 27mmj mmmwm I Patented A t. 29, 1930 UNITED STATES PATENT orrlce w snnmr semen, or cnrcaoo, rnnmors, assmnomrv mnsim assummrs, To run rmmorrr comranr, on NEW roam. N. Y., A oonrona'rron or DELAWARE METHOD 0] PREPARING KE'IALLO-SILIOATES Application filed A ril 11, ms. ,Berlal m. 22,258.

The invention relates to the production of metallo-silicates, and in particular to a novel method of procedure in combining the reagents utilized in what is commonly called the wet method or precipitation process of preparin synthetic zeolites. The invention is particu arly adaptable to the requirements of that class of 'wet method processes 'which involves employment of concentrated solutions of the reagents and which is typified in the process forming the subj ect-matter of my former Patent No. 1,515,007 of November 11, 1924.

Incidental to .the use of concentrated solutions of the selected reagents, is the almost immediate formation of a gel which embraces substantially all of the constituents of the component solutions. In view of the rapiditywith which reaction takes place and formation of the gel is effected, it is essential that care be taken in the mixing to avoid what might be called preliminary or intermediate reactions which must later be overcome, and

to insure that the reaction mass throughout shall constitute a homogeneous precipitate of predetermined. composition.

I have found that the ordinary methods of mixing are not conducive to o taining a roduct' possessing the desired character-- istics. Particularly objectionable is the usual method of adding one solution to the bulk of the other, even though the addition is accompanied by vigorous stirring. Assumingthat it is proposed to add a solution of sodium-silicate to a solution of aluminum sulphate in proper proportion to produce a base exchange material, it is inevitable that during the first stages of the mixing there will be formed hydrated aluminum silicates of variable composition, and that in .order to attain the anticipated sodium aluminum silicate, further reaction must result on addition of the remainder of the silicate solution. When the intermediate products are'precipi- .tated, which will occur under certain conditions, the subsequent'conversion of these to the desired end product is extremely diflicult. Similar conditions will prevail u on addition of the aluminum sulphate to t 'e'sodium silicate. 1

The difliculties referred to are accentuated.

when concentrated solutions are employed, due to the rapidity of the precipitation and the firmness of the gel that is forined. If a relatively large proportion of aluminum sulphate is to be used in the endeavor to increase the density of the final product, there is the possibility that in some portion of the gel the alkali will have been completely neutralized and the corresponding product will have no base exchanging roperty.

These and other 0 jections to prior procedure in the mixing of quick reacting solutions to obtain a precipitate in the form' of a gel will be overcome by the present invention which, generally stated, comprises the pro-' gressive flowing together of constituent parts of the react solutions in the proper proportions to attain the desired combination. In order that the invention maybe betterunderstood, I- present in the accompanying drawings a diagrammatic sketch of apparatus suitable for practicing the. invention.

In the drawing the numerals '10 and 11 re resent tanks or vessels for-holding the.

so utions to be mixed, Each of these tanks has an orifice at the bottom thereof, to which are connected. respectively the pipes 12 and One oft ese pi es, in

fluid passing therethrough directly into the path of the hquidflowin from the pi e 12.

The tanks, orifices anfi pipes may e proportioned to discharge the solutionsin any desired ratio. I

A; dra'w-ofl pipe 16 leads from the bottom of the mixing chamber to a suitable receptacle1 17 in which the compound sets to a firm ge As an example of operation, let us assume that the tanks 10 and 11 are of equal dimension and that the pipes 12 and 13 and the orifices in the respective tanks are proportioned to permit equal withdrawal of the solution. Let us further assume that 7 liters of an aqueous solution of commercial aluminum sulphate containing 70 grams per liter is placed in the vessel 10 and that 21.3 kg. of commercial water glass diluted to 75 liters with water is'placed in the vessel 11. The cocks 12 and 13'are now opened, whereupon the solutions will discharge at the same rate thro gh thepipes m and 13 and flow together adjace'i'it'gthe discharge ends of the said pipes within'th'emixing'chamber 14. Inasmuch as the reaction and the formation of a gel follows soon after mixing, it is desirable that the material shall remain within the chamber 14 only long enough to accomplish a fairly uniform commixing of the solutions, which is attained by the turbulence produced by their discharge in the mixing chamber. A

quick escape is provided through the pipe 16 and by the time the outlet into the receptacle 17 is reached the reaction has'been completed and the compound is in condition for setting, which takes place in the receptacle 17 during the continuing influx of more of the material into the receptacle. After setting, the el is dried and broken up.

odification of apparatus and proportioning thereof to meet the requirements of any using the method of the particular practice is Well within the skill of those versed .in the art.

While the chief objectof this invention is the provision of a method of mixing liquids of the nature described, which will insure a homogeneous product of predetermined chemical composition, there are several other advantages which may be derived from its use.- For exam 1e, I am able to employ successfully considerably stronger solutions than would be possible with the usual method of mixing, thereby efl'ecting material economies in handling and drying the roduct.

A further advantage accruing mm the use of this procedure is that higher mixing tem peratures may safely be employed. In the example cited in my Patent No. 1,515,007 I statetha-t the solutions are preferably cooled to about '59 0., in order that fluidity be retained sufiiciently long to provide for thorough mixing and subsequent handling. By

however, thorough and uni orm mixin is accomplished so quickly that an exten ed period of fluidity is not required. In conse quence, the procedure may be carried on at higher temperatures, such as normal, room temperatures, thus eliminating the necessity for refrigeration and the equipment required therefor.

I claim:

' 1. In the manufacture of gels'b interaction of concentrated reacting solutions, the process which comprises contacting two such solutions together in "small proportionate amounts-in a coalescing flow, continuing the resent invention,

flow and effecting mixing in transit, collecting the flowing mixture in a receiver and allowinlg development of gel in said receiver.

2. n the manufacture of gel zeolites by admixture of a solution containing silicate with a solution containing alumina, the process which comprises flowing small-proportioned streams of the silicate solution and of the alumina containing solution into mutual contact in interfering jets, completing the mixture in transit, collecting the mixturethus produced and delivering it through a conduit to a receiver, and allowing development of gel in said receiver.

3. The method of preparing uniform gels from solutions adapted to react quickl to form thick elatinous precipitates, w ich comprises coa escing relatively small propormixed solutions and allowing the resulting -mixture to set to a gel.

In testimony whereof I have hereunto signed my name.

ABRAHAM SIDNEY BEHRMAN. 

